Foldable Composite Panel with Compression Relief Hinge

ABSTRACT

According to an exemplary embodiment, a composite panel includes a primary layer ( 102, 120   a ) that includes a primary hinge ( 122   a ). The primary hinge ( 122   a ) is defined by at least one fold line. The composite panel further includes a reinforcing layer ( 110, 136   a ) that includes a compression relief hinge ( 140   a ). The compression relief hinge ( 140   a ) is defined by a pair of distal fold lines ( 142   a , 146 a ) and a medial fold line ( 144   a ) that Is disposed between and spaced apart from the distal fold lines ( 142   a , 146 a ). The primary hinge ( 122   a ) overlies the compression relief hinge ( 140   a ) so that when the composite panel is folded about the primary hinge ( 122   a ), the composite relief hinge ( 140   a ) buckles away from the primary hinge ( 122   a ).

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 60/754,929, filed Dec. 29, 2005, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

This invention relates generally to packaging, and in particular, to cartons that include multi-layer panels that are folded to form a corner of a carton.

BACKGROUND OF THE INVENTION

Stronger carton walls are desirable for securely packaging items and for transporting heavy items. One method of strengthening selected walls or portions of a carton is to thicken them. For example, a reinforcing layer can be attached to a primary layer to form a composite panel that defines one or more composite walls or portions of the carton. However, the increased thickness of such a composite panel creates increased folding resistance when folding the composite panel, for example, to form a corner of the carton.

The increased folding resistance is due to portions of the reinforcing layer being in compression and to portions of the primary layer being in tension. The folding resistance caused by the tension and compression causes multiple problems including cracking or other damage to the primary and/or reinforcing layer, an irregular or otherwise aesthetically unappealing corner of the carton, and interference with the ability of a machine to fold the composite panel during the packaging process. What is needed is a foldable multi-layer panel that can be easily folded to provide a corner of a carton.

SUMMARY OF THE INVENTION

The various embodiments of the present invention overcome the shortcomings of the prior art by providing a multi-layer or composite panel with an arrangement of overlying aligned hinges, including a compression relief hinge and a primary hinge, that facilitate folding the composite panel. The compression relief hinge is formed in one of the layers of the composite panel and, as the composite panel is folded along the primary hinge, the compression relief hinge bulges away from the primary hinge to reduce congestion in the folding area. Thereby, the thickness of the material in the area where the composite panel is folded is essentially reduced and the composite panel can be easily folded along the primary hinge.

According to an exemplary embodiment, a composite panel includes a primary layer that includes a primary hinge. The primary hinge is defined by at least one fold line. The composite panel further includes a reinforcing layer that includes a compression relief hinge. The compression relief hinge is defined by a pair of distal fold lines and a medial fold line that is disposed between and spaced apart from the distal fold lines.

At least a portion of the reinforcing layer is secured to the primary layer, such that the primary hinge and the compression relief hinge are aligned. In certain embodiments, the primary layer and the reinforcing layer are secured to one another on opposite sides of the compression relief hinge. The compression relief hinge portion of the reinforcing layer is not secured to the primary layer so that the compression relief hinge can move with respect to the primary hinge. The primary layer and the reinforcing layer are aligned such that a fold line that defines the primary hinge is disposed between the distal fold lines that define the compression relief hinge. In certain embodiments, a fold line that defines the primary hinge is aligned with a medial fold line that defines the compression relief hinge. In sum, the primary hinge overlies the compression relief hinge so that when the composite panel is folded about the primary hinge and the compression relief hinge, the distal fold lines and the medial fold line cooperate to form a furrow that buckles away from the primary hinge.

The spaced apart medial and distal fold lines define bulge panels. In certain embodiments, the distances between the fold lines that define the compression relief hinge, or otherwise the widths of the bulge panels, are functions of the thickness of the layers of the composite panel.

Further, in certain embodiments, the dimensions of the fold lines that define the compression relief hinge are functions of the thicknesses of the layers of the composite panel. The medial and distal fold lines can have widths and depths such that the bulge panels or otherwise the material of the compression relief hinge can collapse the cavities defined by the medial and distal fold lines as the compression relief hinge is folded along the fold lines. The collapsing of the cavities facilitates folding the bulge panels or otherwise the furrowing of the compression relief hinge. In such embodiments, the cavity of each of the distal fold lines can be formed in a first surface or side of the reinforcing layer and the cavity of the medial fold line can be formed in a second surface or side of the reinforcing layer.

In certain embodiments, the width of the medial fold line is greater than the width of the distal fold lines. A wider fold line is typically easier to buckle, collapse, or initiate a fold along. To form a wider medial fold line, in certain embodiments, the medial fold line is formed from a group of three or more substantially parallel weakened lines that are substantially adjacent to one another or otherwise directly abutting one another. The group of weakened lines cooperates such that the medial fold line collapses when the composite panel is folded. To that end, at least one in the group of weakened lines is comparatively weaker than the other score lines in the group. In other words, the comparatively weaker weakened line can be folded more easily than the others, and thus, defines the preferred location of the inward collapse of the medial fold line. The comparatively weaker weakened line is made more easily foldable by means of any composition, arrangement, combination, or series of at least one slit, cut, half cut, deep score, crimp, or perforation.

Briefly, the present invention is described in the context of a carton having first and second at least partially composite walls that are hingedly connected to one another. The first wall is a reinforced top wall and the second wall is an end wall that is at least partially reinforced to provide a stronger handle opening. Specifically, the reinforced end wall includes a reinforced end flap that is hingedly connected to the reinforced top wall. The reinforced top wall includes a primary layer and a reinforcing layer, wherein at least a portion of the reinforcing layer is secured to the primary layer in a face-contacting arrangement. The reinforced end wall includes a primary layer that is hingedly connected to the primary layer of the top wall along a primary hinge, and a reinforcing layer that is hingedly connected to the reinforcing layer of the top wall along a compression relief hinge. The reinforcing layer of the end wall is secured to the primary layer of the end wall in a face-contacting arrangement.

The foregoing has broadly outlined some of the aspects and features of the present invention, which should be construed to be merely illustrative of various potential applications of the invention. Other beneficial results can be obtained by applying the disclosed information in a different manner or by combining various aspects of the disclosed embodiments. Accordingly, other aspects and a more comprehensive understanding of the invention may be obtained by referring to the detailed description of the exemplary embodiments taken in conjunction with the accompanying drawings, in addition to the scope of the invention defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an exemplary blank for forming a carton.

FIG. 2 is a detail view of a compression relief hinge formed in the blank of FIG. 1.

FIGS. 3 and 4 perspective views illustrating steps for forming a carton, the carton being formed from the blank of FIG. 1.

FIGS. 5 and 6 are sectional perspective views of a portion of the carton of FIGS. 3 and 4 illustrating steps for forming the carton.

FIGS. 7 and 8 are sectional side elevation views of the portion of the carton of FIGS. 5 and 6.

FIG. 9 is an end elevation view of an exemplary arrangement of dies for forming a compression relief hinge in a layer of material.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosed herein. It must be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms, and combinations thereof. As used herein, the word “exemplary” is used expansively to refer to embodiments that serve as illustrations, specimens, models, or patterns. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of particular components. In other instances, well-known components, systems, materials, or methods have not been described in detail in order to avoid obscuring the present invention. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

Referring now to the drawings in which like numerals indicate like elements throughout the several views, the drawings illustrate certain of the various aspects of an exemplary embodiment of a carton having walls that are at least partially defined by a composite panel that includes multiple layers of sheet material. The composite panel includes an arrangement of overlying hinges that facilitate folding the composite panel to fold the walls. Specifically, at least one of the layers of sheet material includes a compression relief hinge that buckles away from a hinge in another of the layers of sheet material to facilitate folding the composite panel to form a corner of the carton.

It should be understood that the arrangement of overlying hinges is illustrated in the context of an exemplary carton for purposes of teaching and that the scope of the invention is not limited to the elements or configuration of the exemplary carton. Rather, the compression relief hinge can be applied to any container, carrier, carton, insert, package, panel, structure, or the like that includes panels or walls formed from multiple layers of sheet material and that are folded.

Referring to FIGS. 1 and 4, an exemplary carton 200 is formed from an exemplary blank 100, which is preferably a single sheet of suitable substrate. It is to be understood that, as used herein, the term “suitable substrate” includes all manner of foldable sheet material such as paperboard, corrugated board, cardboard, plastic, combinations thereof, and the like. In the illustrated embodiments, a unitary blank 100 is used to form the carton 200, although it should be recognized that two or more blanks may be employed to provide the carton structure.

Referring to FIG. 1, the exemplary carton blank 100 is further described. For purposes of reference, the side of the carton blank 100 shown in FIG. 1 is defined as the outside surface, and the opposing side of the carton blank 100 is defined as the inside surface. The carton blank 100 includes primary panels 102, 104, 106, 108 and a reinforcing panel 110 that are hingedly connected one to the next along fold lines 112, 114, 116, 118. It should be understood that, in alternative embodiments, the reinforcing panel 110 can be separate from the primary panels of the blank 100.

End flaps are hingedly connected to opposing edges of each primary panel 102, 104, 106, 108 and to opposing edges of the reinforcing panel 110. The blank 100 is substantially symmetric such that the end flaps that are hingedly connected to the opposite ends of each primary panel are substantially similar. Accordingly, the end closure structures of the carton 200 are substantially identical and like references have been used with a suffix “a” or “b” affixed to distinguish one end of the carton 200 from the other. Thus, the description of an element or group of elements having a suffix “a” can be applied to a like-numbered element or group of elements having a suffix “b”. In certain instances, for clarity, only one of the like elements is described unless a description of the other or both of the like elements is useful for understanding the invention.

Top end flaps 120 a, 120 b are hingedly connected to top panel 102 along fold lines 122 a, 122 b, first side end flaps 124 a, 124 b are hingedly connected to first side panel 104 along fold lines 126 a, 126 b, bottom end flaps 128 a, 128 b are hingedly connected to bottom panel 106 along fold lines 130 a, 130 b, and second side end flaps 132 a, 132 b are hingedly connected to second side panel 108 along fold lines 134 a, 134 b. Further, reinforcing end flaps 136 a, 136 b are connected to the reinforcing panel 110 by compression relief hinges 140 a, 140 b.

Referring to FIGS. 1 and 2, the compression relief hinge 140 a includes a group of fold lines that define bulge panels. In the exemplary embodiment, the compression relief hinge 140 a includes an inner distal fold line 142 a, a medial fold line 144 a, and an outer distal fold line 146 a. The fold lines 142 a, 144 a define a first bulge panel 148 a and the fold lines 144 a, 146 a define a second bulge panel 160 a. It should be noted that the medial fold line 144 a can include a group of adjacent substantially parallel weakened lines, as described in further detail below. The compression relief hinge 140 a further includes apertures 152 a that interrupt the fold lines 142 a, 144 a, 146 a so as to increasingly facilitate buckling, folding, or collapsing the compression relief hinge 140 a, as described in further detail below.

The fold lines 142 a, 144 a, 146 a are substantially parallel to one another and are spaced from one another by a distance D1. In certain embodiments, the distance D1 is a function of the thickness or caliper of the blank 100 or of the layers of sheet material that define a composite panel, as described in further detail below. The width of each of the bulge panels 148 a, 150 a is accordingly substantially equal to the distance D1.

As described in further detail below, the widths of the fold lines 142 a, 144 a, 146 a can be selected to facilitate buckling of the compression relief hinge 140 a. It should be understood that wider fold lines are easier to buckle, collapse, or initiate a fold along. Typically, a single die is needed to form a fold line, as described in further detail below. To form a wider fold line, a group of dies can be used. In the exemplary embodiment, the width of the medial fold line 144 a is selected to be wider than the widths of the distal fold lines 142 a, 146 a. Thereby, folding or buckling is facilitated to a substantially greater degree along the medial fold line 144 a than along the distal fold lines 142 a, 146 a.

In alternative embodiments, the compression relief hinge 140 a includes more than three fold lines and more than two bulge panels. For example, a compression relief hinge can include two medial fold lines and two distal fold lines that define three bulge panels.

The carton 200 can be formed according to the following non-limiting method. Referring to FIGS. 3 and 4, a tubular structure can first be formed by at least partially securing the outside surface of the reinforcing panel 110 to the inside surface of the top panel 102. Further, the outside surfaces of the reinforcing end flaps 136 a, 136 b are at least partially secured to the inside surfaces of respective top end flaps 120 a, 120 b. The reinforcing panel 110 and reinforcing end flaps 136 a, 136 b are secured to the primary panel 102 and the primary end flaps 120 a, 120 b such that the fold lines 122 a, 122 b are aligned with the compression relief hinges 140 a, 140 b, respectively. Referring momentarily to FIG. 5, the fold line 122 a is aligned with the compression relief hinge 140 a so as to lie between the distal fold lines 142 a, 146 a. It should be noted that the bulge panels 148 a, 150 a are not secured to the top panel 102 or top end flap 120 a. Rather, the bulge panels 148 a, 150 a can move independently from the top panel 102 and the top end flap 120 a.

Hereinafter the term “primary layer” refers to the layer of material defined by or including the top panel 102 and the top end flap 120 a and the term “reinforcing layer” refers to the layer of material defined by or including the reinforcing panel 110 and reinforcing end flap 136 a. Once secured together, the primary layer and the reinforcing layer define a foldable composite panel. Further, the fold line 122 a that is disposed in the primary layer is hereinafter referred to as the primary hinge along which the composite panel is folded.

In the exemplary embodiment, the inner surface of the primary layer is secured to the reinforcing layer at two general locations on opposite sides of the compression relief hinge 140 a.

As shown in FIGS. 3 and 4, the primary end flaps 120 a, 124 a, 128 a, 132 a are folded and secured to form a first end wall of the carton 200. Accordingly, the composite panel is folded along the primary hinge 122 a Consequently, referring to FIGS. 5-8, the compression relief hinge 140 a portion of the reinforcing layer is compressed between the reinforcing panel 110 and the reinforcing end flap 136 a. In cartons without a compression relief hinge 140 a, the material that makes up the compression relief hinge 140 a would gather, compress, and be forced against the inside surface of the area of the primary layer near the primary hinge 122 a, thereby resisting folding along the primary hinge 122 a. However, the fold lines 142 a, 144 a, 146 a of the compression relief hinge 140 a facilitate pivoting movement of the bulge panels 148 a, 150 a, or otherwise folding, buckling, collapsing, flexing, or crumpling of the compression relief hinge 140 a, such that folding resistance due to compression of the material of the compression relief hinge 140 a portion of the reinforcing layer is relieved.

Referring to FIGS. 5 and 7, as the compression relief hinge 140 a buckles, it forms a furrow E. Specifically, the bulge panels 148 a, 150 a fold along the medial fold line 144 a and the distal fold lines 142 a, 146 a, the outside surfaces of the bulge panels 148 a, 150 a move toward one another, and the portion of the reinforcing layer adjacent the medial fold line 144 a moves away from the corner defined by the primary hinge 122 a.

Methods of forming and arranging a group of fold lines to provide a compression relief hinge are described in further detail. As used herein, the term “fold line” refers to all manner of lines that define hinge features of the blank, facilitate folding portions of the blank with respect to one another, or otherwise indicate optimal panel folding locations for the blank. A fold line is typically a scored line, an embossed line, or a debossed line. It should be understood that fold lines can each include elements that are formed in the substrate of the blank including perforations, a line of perforations, a line of short slits, a line of half-cuts, a single half-cut, a cut line, an interrupted cut line, slits, scores, any combination thereof, and the like. The elements can be dimensioned and arranged to provide the desired functionality. For example, a line of perforations can be dimensioned or arranged to provide a fold line with a certain degree of weakness that may be greater than the weakness of a fold line formed from a scored line.

The fold lines 142 a, 144 a, 146 a can be formed in the blank 100 by the following non-limiting method to form the compression relief hinge 140 a. It should be understood that the fold lines 142 a, 144 a, 146 a can be formed in the blank 100 via any known or yet to be developed process, such as stamping or scoring. In the exemplary embodiments, the fold lines are created with an arrangement of tools, such as dies, where each die is for forming a weakened line of a certain width and each fold line includes one or more weakened lines formed by a corresponding number of dies.

It should be understood that the method described below is for forming an alternative arrangement of a compression relief hinge that is illustrated in FIG. 9. The embodiment of FIG. 9 and the embodiment of FIG. 7 are substantially similar with the exception that depressions that define the distal fold lines 142 a, 146 a are formed in different sides or surfaces of the reinforcing layer in the different embodiments. It should be understood that the method described below can be altered to produce the embodiment of FIG. 7, for example, by first forming the medial fold line in a first surface of the blank and flipping the blank before forming the distal fold lines in a second surface of the blank.

Each die can include a relatively dull edge suitable for stamping an impression, a relatively honed or sharp edge that makes a line of cuts in the blank 100, or a combination of alternating dull and honed edges that create alternating scores and cuts or half cuts. Referring to FIG. 9, an end view shows that one type of die 900 that can be used to form a weakened line that alternates between short slits and score lines and another type of die 902 can be used to form a score line.

The exemplary arrangement or configuration of dies 900, 902 is used to form the arrangement of fold lines 142 a, 144 a, 146 a that define the compression relief hinge 140 a. The distal fold lines 142 a, 146 a are formed with a single die 900. The medial fold line 144 a is formed with a group of three dies 900, 902, where the outermost dies 900 form a weakened line that is a score line and the centermost die 902 forms a comparatively weaker weakened line that alternates between short slits and score lines. Accordingly the medial fold line 144 a is formed from three substantially parallel adjacent weakened lines and has three times the width of the distal fold lines 142 a, 146 a. It should be understood that, according to the exemplary method, the number of dies that are used to form each fold line determines the width of the fold line. The depths of the weakened lines, with respect to the surface of the layer of material, are determined by the force used to score the material and by the characteristics of the material.

The centers of the weakened lines of the medial fold line 144 a are disposed at substantially equal distances D3 from one another. The distance D2 between the center of a distal fold line 142 a, 146 a and the center of the nearest of the group of weakened lines that form the medial fold line 144 a is greater than the distance D3 between the weakened lines of the medial fold line 144 a.

In alternative embodiments, the medial fold line 144 a can be formed by more than three dies. For example, a medial fold line can be formed with four dies. For such a medial fold line, one or more of the centermost dies forms a weakened line that alternates between short slits and score lines and the remainder of the dies forms weakened lines that are score lines.

In additional alternative embodiments, configurations that form more that three fold lines are contemplated. For example, a configuration of dies can form two medial fold lines inside of two distal fold lines.

To optimally control the direction of collapse, fold lines can be formed in either side or surface of a reinforcing layer, or in both sides or surfaces of a reinforcing layer. For example, referring again to FIGS. 7 and 8, the medial fold line 144 a is formed in the outer side or surface of the reinforcing layer and the distal fold lines 142 a, 146 a can be formed in the inner side or surface of the reinforcing layer. In contrast, FIG. 9 shows an alternative arrangement wherein the medial fold line 144 a is formed in the inner side or surface of the reinforcing layer. In the configuration shown in FIGS. 7 and 8, the fold lines 142 a, 144 a, 146 a are formed in a side of the reinforcing layer such that as the compression relief hinge 140 a folds or buckles, the channels, impressions, or cavities defined by the fold lines 142 a, 144 a, 146 a collapse to provide compression relief.

The present invention has been illustrated in relation to a particular embodiment which is intended in all respects to be illustrative rather than restrictive. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. For example, as used herein, directional references such as “top”, “base”, “bottom”, “end”, “side”, “inner”, “outer”, “upper”, “middle”, “lower”, “front” and “rear” do not limit the respective walls of the carton to such orientation, but merely serve to distinguish these walls from one another. Any reference to hinged connection should not be construed as necessarily referring to a junction including a single hinge only; indeed, it is envisaged that hinged connection can be formed from one or more potentially disparate means for hingedly connecting materials.

The above-described embodiments are merely exemplary illustrations of implementations set forth for a clear understanding of the principles of the invention. Variations, modifications, and combinations may be made to the above-described embodiments without departing from the scope of the claims. All such variations, modifications, and combinations are included herein by the scope of this disclosure and the following claims. 

1. A foldable panel of composite sheet material for forming at least a portion of a carton, the panel comprising: a primary layer comprising a primary hinge, the primary hinge comprising at least one fold line; a reinforcing layer comprising a compression relief hinge, the compression relief hinge comprising: a pair of distal fold lines; and at least one medial fold line disposed between and spaced apart from the pair of distal fold lines; wherein: at least a portion of the reinforcing layer is secured to the primary layer; and the primary hinge and the compression relief hinge are aligned.
 2. The foldable panel of claim 1, wherein the primary hinge is aligned with the compression relief hinge such that the primary hinge is disposed between the pair of distal fold lines.
 3. The foldable panel of claim 1, wherein the width of the medial fold line is greater than the width of the distal fold lines.
 4. The foldable panel of claim 1, wherein the medial fold line comprises a plurality of adjacent weakened lines.
 5. The foldable panel of claim 1, wherein the distance between the medial fold line and a distal fold line is a function of the thicknesses of the layers.
 6. The foldable panel of claim 1, wherein the distal fold lines are formed in a first surface of the reinforcing layer and the medial fold line is formed in a second surface of the reinforcing layer.
 7. The foldable panel of claim 1, wherein bulge panels are defined by the distal fold lines and the medial fold line.
 8. The foldable panel of claim 1, wherein the compression relief hinge can fold along the distal fold lines and the medial fold line to form a furrow as the foldable panel is folded along the primary hinge.
 9. The foldable panel of claim 4, wherein at least one of said plurality of adjacent weakened lines is comparatively weaker than the other of said plurality adjacent weakened lines.
 10. The foldable panel of claim 9, wherein said plurality of adjacent weakened lines comprises a pair of endmost weakened lines and at least one centermost weakened line, wherein said at least one centermost line comprises said comparatively weaker line.
 11. The foldable panel of claim 9, wherein said comparatively weaker line comprises any of the following: slit; cut; half cut; score; crimp; and perforation.
 12. The foldable panel of claim 1, wherein said primary layer is secured to said reinforcing layer on opposite sides of said compression relief hinge.
 13. The foldable panel of claim 1, wherein at least one of said distal fold lines is formed from a plurality of substantially parallel adjacent weakened lines.
 14. The foldable panel of claim 1, wherein said primary hinge comprises a plurality of substantially parallel fold lines formed in said primary layer.
 15. A method for forming a corner of a carton by folding a composite panel formed from at least a primary layer and a reinforcing layer, the method comprising: defining a primary hinge in said primary layer; securing at least a portion of said reinforcing layer to said primary layer on both sides of said primary hinge; and defining a compression relief hinge in said reinforcing layer, comprising: defining a medial fold line; aligning said medial fold line with said primary hinge; and defining at least a first and a second distal fold line each being substantially parallel to said medial fold line, said medial fold line being disposed between said distal fold lines and being spaced apart from each of said distal fold lines.
 16. The method of claim 15, wherein said primary hinge extends at least partially across said primary layer.
 17. The method of claim 15, wherein said medial fold line comprises at least three weakened lines.
 18. The method of claim 17, wherein at least a centermost one of said weakened lines is weaker than the outermost ones of said weakened lines.
 19. The method of claim 15, wherein defining said medial fold line comprises creating a score line in said reinforcing layer and extensively weakening a centermost portion of said score line.
 20. The method of claim 15, further comprising folding said composite panel along said primary hinge such that said compression relief hinge buckles away from said primary hinge. 